Lotion shampoos are widely accepted due to their ease of use, including spreading the shampoo through the hair. However, when particulate active ingredients are used in lotion shampoos suspending active ingredients presents problems of various degrees. Suspension is desired so that the active concentration is the same, or close to the same, over several uses.
The prior art has recognized the need/desire for adequate suspension systems. Japanese Application with Open for Public Inspection No. 60,810, May 19, 1977 (Lion Fat & Oil), discloses shampoos containing 5% to 50% of an anionic surfactant, 1% to 10% of a fatty acid diethanol amide, 0.1% to 10% of an insoluble fine powder and 1% to 10% of an ethylene glycol ester. U.S. Pat. No. 4,470,982, to Winkler discloses similar compositions containing from 11% to 20% of an anionic surfactant, from 4% to 6% of a suspending agent, from 2% to 4% of an amide, a particulate antidandruff agent and water. British Pat. No. 1,051,268, Dec. 14, 1966 to Colgate-Palmolive Company discloses selenium sulfide shampoos containing suspending agents.
While these references disclose suspending antidandruff actives, they do not disclose compositions containing selenium sulfide and low levels of suspending agents.
It has been surprisingly found by the present inventors that certain selenium sulfide compositions can utilize low levels of suspending agents.
It is an object of the present invention, therefore, to provide stable selenium sulfide lotion shampoos.
It is a further object of the present invention to provide selenium sulfide lotion shampoos utilizing low levels of suspending agents.
It is a still further object of the present invention to provide methods of shampooing hair with improved selenium sulfide compositions.
These and other objects will become readily apparent from the detailed description which follows.
Unless otherwise indicated, all percentages and ratios herein are by weight.